Power module and air conditioner

ABSTRACT

An efficient heat diffusing structure comprising a power module having a mounting substrate that has a high thermal conduction efficiency. The mounting substrate is comprised of a mounting surface on which an electric power circuit for controlling electric power is mounted, and a heat dissipating surface that has a corrugated section formed thereon that serves to dissipate heat. This heat diffusing structure allows the size of the device to be reduced, and also allows costs to be reduced.

TECHNICAL FIELD

[0001] The present invention relates to a power module and an airconditioner comprising a power module. More particularly, the presentinvention relates to a heat dissipating structure for improving the heatdissipating efficiency of a power module on which circuit componentsthat generate a great deal of heat are mounted, and the modulization ofa power module that uses an inverter circuit to convert commercial acpower to ac power having a predetermined frequency.

BACKGROUND ART

[0002] In order to control a device at a predetermined frequency, aninverter circuit will be used to rectify commercial ac power to dcpower, and then convert the dc power to ac power that is controlled at apredetermined frequency.

[0003] The inverter circuit is formed by combining a rectifying stack, asmoothing condenser, a power transistor, and the like. These circuitcomponents continue to be integrated, and an intelligent module whichpackages a drive circuit and a power element together is now beingmarketed. In addition, one type of electric power unit needed to drivethe inverter includes a converter that rectifies commercial ac power todc power, and improves harmonic suppression and efficiency. Moreover, ithas been proposed that this electric power unit employs a power switchand the like.

[0004] The converter that converts commercial ac power to dc power, andthe inverter that converts dc power to ac power of a predeterminedfrequency, are comprised of heat generating components such as diodesand power switches, and thus must include a heat dissipating structure.For example, it is possible to achieve a cooling effect on theelectrical components by using an aluminum substrate to mount theelectrical components, due to the cooling effect provided by the surfaceof the aluminum substrate that is opposite the mounting surface.

[0005] However, because the integration of these electrical componentscontinue, a great deal of heat will be generated thereby and the heatdissipating capabilities of the aluminum substrate will be insufficient.Because of this, it is thought that the heat dissipating capabilitieswill improve by fixing a large number of plate shaped heat dissipatingfins onto the bottom surface of the aluminum substrate.

[0006] When the heat dissipating plates are added, efficient heattransfer cannot be expected at the connecting surface between thealuminum substrate and the heat dissipating fins because the portionthat connects these two elements has a great deal of heat resistance. Inorder to address this problem, increasing the size of the heatdissipating fins to increase the heat dissipating capacity thereof hasbeen considered. However, this will increase the overall size of thedevice and make it difficult to lower costs.

[0007] It is an object of the present invention to provide a powermodule that has an efficient heat dissipation structure, that is small,and that allows cost to be lowered.

[0008] In addition, because there are many instances in which theconverter and inverter are placed in barracks or in specialized modules,the shape of the completed component is large, the thermal designthereof must take into consideration its spatial layout design andthermal state, and the design of the converter and inverter will beextremely difficult.

[0009] In addition, a controller for controlling the inverter circuit iscomprised of a microcomputer, and the controller and the invertercircuit are connected by a harness or the like. When a drive signal istransmitted via this harness, there is a concern that noise will beeasily transferred and be involved in malfunctions.

[0010] Furthermore, there are other problems that it is difficult todiagnose a failure part, it is difficult to specify the components toexchange and it is complicate to exchange a component, since the controlof the inverter is high efficient.

[0011] Because there is a great deal of exposed solder, component lead,and the like for mounting each component, there is also a concern thattracking accidents will occur due to the infiltration of corrosion,dust, or small animals therein.

[0012] Operational control of an air conditioner is conducted bycontrolling the amount of refrigerant that circulates in the refrigerantcircuit with the compressor. This type of compressor uses an invertercircuit to control the operational frequency thereof, and thus includesthe problems with the inverter circuit described above. In particular,it is desirable for the air conditioner to be made compact by reducingthe size of each component therein, and to simplify the layout andthermal design thereof. Furthermore, there is a need to preventmalfunctions due to the effects of noise, as well as a need to preventthe ill effects of corrosion, dust, and the infiltration of smallanimals therein. In particular, when the inverter circuit is installedin the outdoor unit of an air conditioner, there are concerns about thedeterioration thereof that accompanies environmental changes such astemperature variations over a long period of time and wind and rain, andthe infiltration of insects and other small animals. The effects ofthese problems need to be eliminated to the greatest degree possible.

[0013] It is another object of the present invention to provide a powermodule that is constructed such that the portions thereof that areexposed, such as the harness, the solder, and component leads, arereduced to the greatest degree possible, the effects of noise areeliminated, the effects of corrosion, dust, and the infiltration ofsmall animals are eliminated, and special layout and thermal designs arenot necessary.

DISCLOSURE OF THE INVENTION

[0014] A power module according to claim 1 of the present invention iscomprised of a bare chip component that forms an electrical powercircuit for controlling electrical power, a mounting substrate on whichthe bare chip component is mounted, and a molding material formed froman insulating resin that molds to the surface of the mounting substrateon which the bare chip component is mounted.

[0015] In the power module according to claim 1 of the presentinvention, the connection between the bare chip component and the wiringon the mounting substrate can be formed by wire bonding and the like.Because this wiring is covered by means of the molding material, thewiring can be shortened and the effects of noise can be eliminated. Inaddition, because exposed portions will be eliminated, ill effects fromthe infiltration of corrosion, dust, and small animals can be prevented.

[0016] The power module according to claim 2 of the present invention isthe power module disclosed in claim 1, in which a plurality of bare chipcomponents are mounted on the mounting substrate.

[0017] In the power module according to claim 2 of the presentinvention, the connection between the bare chip components and thewiring on the mounting substrate can be formed by wire bonding and thelike. Because this wiring is covered by means of the molding material,the wiring can be shortened. When a large number of components generateheat, the power module can be constructed such that the heat isdissipated via the aluminum substrate.

[0018] The power module according to claim 3 of the present invention isthe power module disclosed in claims 1 or 2, in which the bare chipcomponent includes an IC chip that is mounted on a printed wiring boardthat is mounted on the mounting surface.

[0019] In the power module according to claim 3 of the presentinvention, circuit components that produce a great deal of heat can beinsulated from those that produce comparatively little heat by formingthe printed wiring board on which the comparatively low heat generatingcircuit components are mounted into a hybrid shape.

[0020] The power module according to claim 4 of the present invention isthe power module disclosed in claims 1 to 3, in which the mountingsubstrate has heat dissipating fins that are integrally disposed on thesurface opposite the surface on which the bare chip component ismounted.

[0021] In the power module according to claim 4 of the presentinvention, if comparatively high heat generating circuit components aremounted on top of the mounting substrate as bare chip components, heatcan be efficiently dissipated therefrom via the heat dissipating fins,and circuit malfunctions can be prevented by maintaining them at asuitable temperature.

[0022] The power module according to claim 5 of the present invention isthe power module disclosed in claims 1 to 4, and further comprises sidewalls that are disposed on the edges of the mounting substrate and whichextend above the surface on which the bare chip is mounted, and in whicha molding material is disposed inside the space formed by the mountingsubstrate and the side walls.

[0023] In this configuration, the task of filling the space formed bythe mounting substrate and the side walls with the molding material canbe made easy, and the bare chip component mounting surface of themounting substrate can be accurately covered.

[0024] The power module according to claim 6 of the present invention isthe power module disclosed in claim 5, in which the side walls arecomprised of plate shaped members that are formed from a synthetic resinand in which a conductive pattern is embedded.

[0025] Here, it becomes possible to use the conductive pattern embeddedin the interior of the side walls to connect the circuit elements, andit also becomes possible to mount circuit elements such as electrolyticcondensers and the like that are difficult to integrate.

[0026] The power module according to claim 7 of the present invention isthe power module disclosed in any of claims 1 to 6, in which the barechip component includes an inverter circuit that converts commercial acpower to ac power having a predetermined frequency, and a controllerthat controls the frequency output from the inverter circuit.

[0027] Here, by directly mounting the inverter circuit and thecontroller for the inverter circuit to the mounting substrate as barechip components and modulizing them, it will not be necessary to againconsider the spatial layout and thermal design of each component, theeffects of noise will be eliminated to the greatest degree possible byshortening the wiring distances, and the infiltration of corrosion, dustand small animals will be prevented.

[0028] The power module according to claim 8 of the present invention isthe power module disclosed in claim 7, in which the inverter circuit iscomprised of a converter that rectifies commercial ac power to dc power,an inverter that converts the output of the converter to ac power, aconverter driver that drives the converter, and an inverter driver thatdrives the inverter.

[0029] Here, each power module can be comprised of one or a plurality ofbare chip components, and the bare chip components can be mounted on thealuminum substrate. Thus, it will not be necessary to again considerspecialized spatial layout and thermal designs thereof.

[0030] The power module according to claim 9 of the present invention isthe power module disclosed in claim 7 or 8, in which the invertercircuit controls the electric power supplied to a compressor in an airconditioner, the compressor controlling the amount of refrigerantcirculating in a refrigerant circuit.

[0031] Here, by modulizing the inverter circuit that controls thecompressor of the air conditioner, the size of the device can bereduced, the effects of noise and ill effects from the infiltration ofcorrosion, dust and small animals can be eliminated, and a highlyreliable device can be provided. In addition, by viewing the powermodule as one component and conducing structural design accordingly, itwill not be necessary to have a different structural design for eachtype of compressor mounted in the air conditioner, and thus the numberof man-hours needed for structural design with respect to the largenumber of different types of compressors available can be greatlyreduced.

[0032] The power module according to claim 10 of the present inventionis the power module disclosed in claim 9, in which the air conditioneris comprised of a fan that produces an air flow that exchanges heat withrefrigerant inside a heat exchanger disposed inside the refrigerantcircuit, and a fan motor that rotatively drives the fan. In addition,the bare chip component further includes a fan motor controller thatcontrols the rotation of the fan motor.

[0033] Here, the size of the device can be reduced by mounting the fanmotor controller comprising bare chip components onto the aluminumsubstrate together with other circuit components and modulizing them,thus eliminating the need to again consider the spatial layout andthermal design thereof.

[0034] An air conditioner according to claim 11 of the present inventionis comprised of an air conditioning unit that exchanges heat between airdrawn therein and refrigerant that circulates inside a refrigerantcircuit and then supplies the heat exchanged air to an indoor space, andan electric power unit that controls the electric power supplied to theair conditioning unit. The electric power unit is comprised of amodulized power module that is comprised of a bare chip component thatforms an electric power circuit for controlling electric power, analuminum substrate on which the bare chip component is mounted, and amolding material that is formed from an insulating resin and which moldsthe surface of the mounting substrate to which the bare chip componentis mounted.

[0035] Here, by modulizing the electric power unit of the airconditioner, the size of the device can be reduced, the effects of noiseand the infiltration of corrosion, dust and small animals can beeliminated, and a highly reliable device can be provided.

[0036] The air conditioner according to claim 12 of the presentinvention is the air conditioner according to claim 11, which furthercomprises a compressor that controls the amount of refrigerantcirculating in the refrigerant circuit, and the bare chip componentcontrols the electric power that is supplied to the compressor andincludes an inverter circuit that converts commercial ac power to acpower of a predetermined frequency, and a controller that controls thefrequency of the output of the inverter circuit.

[0037] Here, the effects of noise can be eliminated by modulizing theelectric power unit that serves to control the electric power suppliedto the compressor of the air conditioner. In addition, although there isa concern that insects, dust, and the like will infiltrate an indoorunit of a separate type of air conditioner because the outdoor unitthereof is placed outside, foreign objects such as small animals anddust that enter into the electric power unit can be prevented fromcausing problems such as short circuiting and the like.

[0038] The air conditioner according to claim 13 of the presentinvention is the air conditioner according to claim 11 or 12, in whichthe air conditioner further comprises a fan that produces an air flowthat exchanges heat with refrigerant inside a heat exchanger disposedinside the refrigerant circuit, and a fan motor that rotatively drivesthe fan. In addition, the bare chip component further includes a fanmotor controller that controls the rotation of the fan motor.

[0039] Here, the size of the device can be reduced by including and thenmodulizing the fan motor controller that controls the rotation of thefan motor of the air conditioner, and thus a highly reliable device inwhich the effects of noise and the infiltration of corrosion, dust, andsmall animals are eliminated.

[0040] A power module according to claim 14 of the present invention hasa mounting substrate that is formed from a member having a high thermalconduction efficiency that comprises a mounting surface on which anelectric power circuit for controlling electric power is mounted, and aheat dissipating surface on which a corrugated section for heatdissipation is formed.

[0041] Here, the heat generated by the circuit components mounted on themounting surface can be efficiently dissipated by means of thecorrugated section formed on the heat dissipating surface of themounting substrate.

[0042] The power module according to claim 15 of the present inventionis the power module disclosed in claim 14, in which the mounting surfaceand the heat dissipating surface form a two-sided mounting substrate.

[0043] Here, heat can be efficiently dissipated from the heatdissipation surface even if the mounting surface is molded with aninsulating synthetic resin and an enclosed type of module is formed.

[0044] The power module according to claim 16 of the present inventionis the power module disclosed in claim 14 or 15, in which the mountingsubstrate comprises a plate shaped substrate formed from an aluminumtype of metal and which has a copper wiring pattern formed on one sidethereof.

[0045] Here, the heat from the circuit components mounted on themounting surface can be efficiently dissipated because an aluminum typeof metal having a high thermo-electric conductivity is used as themounting substrate.

[0046] The power module according to claim 17 of the present inventionis the power module disclosed in any of claims 14 to 16, in which heatdissipating fins comprising an attachment surface that attaches to theheat dissipating surface of the corrugated section, and a fin formationsection on which plate shaped fins are disposed, are installed on theheat dissipating surface of the mounting substrate.

[0047] Here, the attachment surface of the heat dissipating fins has acorrugated shape such that it attaches to the heat dissipating surfaceof the mounting substrate, and the thermal conductive efficiency betweenthe heat dissipating fins and the mounting substrate is improved. Thus,the heat generated from the circuit components mounted on the mountingsubstrate can be efficiently transmitted to the heat dissipating fins,and the efficiency of thermal dissipation can be improved.

[0048] The power module according to claim 18 of the present inventionis the power module disclosed in any of claims 14 to 17, in which thecorrugated section is comprised of plate shaped protrusions havingrectangular cross-sections and which are formed parallel to each other,and grooves that are formed between adjacent protrusions.

[0049] Here, the surface area of the heat dissipating fins of themounting substrate can be enlarged, and the heat dissipation efficiencycan be improved, by means of the protrusions that are rectangular incross-section and the grooves formed in between the adjacentprotrusions. In addition, when the heat dissipating fins are installed,the thermal dissipation effect can be improved because the contactsurface area between the heat dissipating surface of the mountingsubstrate and the attachment surface of the heat dissipating fins isenlarged, and the mutual thermal transmission efficiency thereof isimproved.

[0050] The power module according to claim 19 of the present inventionis the power module disclosed in any of claims 14 to 17, in which thecorrugated section is comprised of plate shaped protrusions that aretriangular in cross-section and which are formed parallel to each other,and grooves that are formed between adjacent protrusions.

[0051] Here, the surface area of the heat dissipating fins of themounting substrate can be enlarged, and the heat dissipation efficiencycan be improved, by means of the protrusions that are triangular incross-section and the grooves formed in between the adjacentprotrusions. In addition, when the heat dissipating fins are installed,the thermal dissipation effect can be improved because the contactsurface area between the heat dissipating surface of the mountingsubstrate and the attachment surface of the heat dissipating fins isenlarged, and the mutual thermal transmission efficiency thereof isimproved.

[0052] The power module according to claim 20 of the present inventionis the power module disclosed in any of claims 14 to 17, in which thecorrugated section is comprised of plate shaped protrusions that aretrapezoidal in cross-section and which are formed parallel to eachother, and grooves that are formed between adjacent protrusions.

[0053] Here, the surface area of the heat dissipating fins of themounting substrate can be enlarged, and the heat dissipation efficiencycan be improved, by means of the protrusions that are trapezoidal incross-section and the grooves formed in between the adjacentprotrusions. In addition, when the heat dissipating fins are installed,the thermal dissipation effect can be improved because the contactsurface area between the heat dissipating surface of the mountingsubstrate and the attachment surface of the heat dissipating fins isenlarged, and the mutual thermal transmission efficiency thereof isimproved.

[0054] The power module according to claim 21 of the present inventionis the power module disclosed in any of claims 14 to 17, in which thecorrugated section is comprised of plate shaped protrusions that aresemi-circular in cross-section and which are formed parallel to eachother, and grooves that are formed between adjacent protrusions.

[0055] In the power module according to claim 21 of the presentinvention, the surface area of the heat dissipating fins of the mountingsubstrate can be enlarged, and the heat dissipation efficiency can beimproved, by means of the protrusions that are semi-circular incross-section and the grooves formed in between the adjacentprotrusions. In addition, when the heat dissipating fins are installed,the thermal dissipation effect can be improved because the contactsurface area between the heat dissipating surface of the mountingsubstrate and the attachment surface of the heat dissipating fins isenlarged, and the mutual thermal transmission efficiency thereof isimproved.

[0056] The power module according to claim 22 of the present inventionis the power module disclosed in any of claims 14 to 17, in which thecorrugated section is comprised of a plurality of protrusions havingtips thereof that are hemi-spherical in shape.

[0057] Here, the surface area of the heat dissipating fins of themounting substrate can be enlarged, and the heat dissipation efficiencycan be improved, by means of the plurality of protrusions whose tips arehemispherical. In addition, when the heat dissipating fins areinstalled, the thermal dissipation effect can be improved because thecontact surface area between the heat dissipating surface of themounting substrate and the attachment surface of the heat dissipatingfins is enlarged, and the mutual thermal transmission efficiency thereofis improved.

[0058] The power module according to claim 23 of the present inventionis the power module disclosed in claim 17, in which the heat dissipatingsurface of the mounting substrate and the attachment surface of the heatdissipating fins comprise protrusions whose tips have a shape incross-section which bulges outward toward the sides thereof further thanthe base thereof, and grooves which are received in between adjacentprotrusions.

[0059] Here, the surface area of the heat dissipating fins of themounting substrate can be enlarged, and the heat dissipation efficiencycan be improved, by means of the protrusions whose tips have a shape incross-section that bulges outward toward the sides further than thebases thereof, and the grooves are received in between the adjacentprotrusions. In addition, by fitting the protrusions and grooves of therespective mounting substrate and heat dissipating fins, movement thatseparates the two members can be regulated, and thus they can bemaintained in the attached state without the use of attachment meanssuch as screws and the like.

BRIEF DESCRIPTION OF THE DRAWINGS

[0060]FIG. 1 is a block diagram showing one example of an electricalpower circuit for an air conditioner.

[0061]FIG. 2 is a lateral view showing an example of the substratestructure of a power module.

[0062]FIG. 3 is a lateral view showing another example of the substratestructure of the power module.

[0063]FIG. 4 is a perspective view showing an example of the substratestructure of the power module.

[0064]FIG. 5 is a perspective view showing another example of thesubstrate structure of the power module.

[0065]FIG. 6 is a perspective view showing an example of the heatdissipating surface of the aluminum substrate.

[0066]FIG. 7 is a perspective view showing another example of the heatdissipating surface of the aluminum substrate.

[0067]FIG. 8 is a perspective view showing another example of the heatdissipating surface of the aluminum substrate.

[0068]FIG. 9 is a perspective view showing another example of the heatdissipating surface of the aluminum substrate.

[0069]FIG. 10 is a perspective view showing another example of the heatdissipating surface of the aluminum substrate.

[0070]FIG. 11 is a perspective view showing an example of the attachmentsurface of the heat dissipating fins.

[0071]FIG. 12 is a perspective view showing another example of theattachment surface of the heat dissipating fins.

[0072]FIG. 13 is a perspective view showing another example of theattachment surface of the heat dissipating fins.

[0073]FIG. 14 is a perspective view showing another example of theattachment surface of the heat dissipating fins.

[0074]FIG. 15 is a perspective view showing another example of theattachment surface of the heat dissipating fins.

[0075]FIG. 16 is a perspective view showing another example of theattachment structure of the aluminum substrate and the heat dissipatingfins.

[0076]FIG. 17 is a perspective view showing another example of theattachment structure of the aluminum substrate and the heat dissipatingfins.

[0077]FIG. 18 is a perspective view showing another example of theattachment structure of the aluminum substrate and the heat dissipatingfins.

[0078]FIG. 19 shows an example in which the heat dissipating fins aredisposed on a surface of the aluminum substrate that is opposite themounting surface thereof.

BEST MODE FOR CARRYING OUT THE INVENTION

[0079] (Structure of the Modulized Electric Power Circuit)

[0080] The details of a power module according to the present inventionwill be described with reference to the figures.

[0081]FIG. 1 is a block diagram showing an example of an electric powercircuit that is employed in an air conditioner.

[0082] As shown in FIG. 1, the electric power circuit is connected to acommercial ac power source 1, and the ac power is supplied to a controlpower unit 2 and a modulized electric power circuit 3.

[0083] The control power unit 2 is made up of a switching power supply,and supplies electrical power to a RA controller 4 that includes amicroprocessor, ROM, and various types of interfaces. Detection signalsfrom a plurality of sensors 5 are input into the RA controller 4. Thesesensors 5 include an outside air thermistor that detects the temperatureof the outside air, a heat exchange thermistor that detects theevaporation temperature and the condensing temperature of a heatexchanger, a discharge line temperature sensor that detects thedischarge line temperature of a compressor, and an intake pressuresensor that detects the intake pressure of a compressor. In addition, aplurality of actuators 6 are connected to and controlled by the RAcontroller 4, and include an electric expansion valve that is disposedin the refrigerant circuit and serves to reduce the pressure of therefrigerant therein, and a four way directional control valve whichserves to switch the operational mode of the refrigerant circuit.

[0084] The electric power circuit 3 primarily serves to control theelectrical power that drives a compressor 7 and a fan motor 8 inresponse to the operational state of the air conditioner, and iscomprised of a converter 31 that rectifies the ac power supplied fromthe ac power source 1 and converts it to dc power, an inverter 32 thatconverts the output of the converter 31 to ac power, a converter driver33 which serves to drive the converter 31, an inverter driver 34 whichserves to drive the inverter 32, a fan motor controller 37 thatgenerates a power supply for driving the fan motor 8, a controller 35that controls the converter driver 33, the inverter driver 34, and thefan motor controller 37, and a communication circuit 36 which transmitsand receives data between the RA controller 4 and the electric powercircuit 3.

[0085] The converter 31 can be configured as a power switch, and can beconfigured to include an active filter circuit that outputs dc power ata fixed voltage with respect to the inverter 32.

[0086] The fan motor 8 can use an inverter circuit and an inverterdriver disposed therein. In this situation, the fan motor 8 isconfigured such that the output of the converter 31 is supplied thereto,and rotational control thereof occurs based on rotational speed commandsignals that are input from the fan motor controller 37.

[0087] As noted above, the fan motor controller 37 is configured suchthat it outputs the rotational speed command signals for the fan motor8. In situations in which the fan motor 8 does not use an invertercircuit disposed therein, it can be configured like the controller forthe compressor 7 to include an inverter, and inverter driver, and thelike.

[0088] The RA controller 4 determines the control variables for eachunit in response to the detected values input from the sensors 5 and thecurrent operational mode, outputs control values to the actuators 6, andtransmits control variables for the compressor 7 and the fan motor 8 tothe controller 35 inside the electrical power circuit 3 via thecommunication circuit 36.

[0089] The controller 35 outputs control values to the converter driver33, the inverter driver 34, and the fan motor controller 37 based uponthe control variables for the compressor 7 and the fan motor 8transmitted from the RA controller 4. Thus, the operational frequency ofthe compressor 7 and the rotational frequency of the fan motor 8 can becontrolled in response to the operational state of the air conditioner.

[0090] By integrating and modulizing the circuit components, andpackaging the heat generating and noise generating components, thecontrollability of the electric power circuit 3 can be improved, andhigh performance control thereof can be performed. In other words, asshown in FIG. 2, the electric power circuit 3 is comprised of aplurality of bare chip components 311, 312, and 313 such as a diode andpower transistor, smoothing condenser, IC chip, and the like that areeach mounted on an aluminum substrate 301 by means of wire bonding,solder, and the like.

[0091] The aluminum substrate 301 can, for example, be comprised of asheet of aluminum nitride having high thermal conductivity and excellentelectrical resistance, and a thin sheet of copper that forms a circuitpattern that is adhered to the surface thereof. If a harness is used toconnect the controller 35, converter 31, inverter 32, converter driver33, inverter driver 34, fan motor controller 37 and the communicationcircuit 36, the harness will be a bundle of connections and willgenerate emission noise in the same way a coil does. By using analuminum substrate 301 that is comprised of a thin copper sheet thatforms a circuit pattern and an aluminum nitride sheet that has the thincopper sheet applied to the surface thereof, the generation of emissionnoise can be suppressed, and an increase in controllability due to areduction in noise can be provided.

[0092] Circuit components that have a high heat output are mounteddirectly to the aluminum substrate 301, such as the bare chip components311 and 312. In addition, the bare chip component 313, such as thecontroller 35 comprised of a one chip microcomputer that includes amicroprocessor, ROM, various interfaces, and the like, is to beseparated from the temperature load and noise generated by other circuitcomponents and can be mounted on top of a standard printed wiring board321. A lead 322 provided on the printed wiring board 322 can be mountedon the aluminum substrate 301 by soldering. As shown in FIG. 2, theprinted wiring board 321 can be disposed at a right angle to themounting surface of the aluminum substrate 301, and as shown in FIG. 3,the printed wiring board 321 can also be disposed parallel to themounting surface of the aluminum substrate 301.

[0093] Thus, by mounting precision components such as microcomputers andthe like to the printed wiring board 321 in a hybrid manner, unnecessarytemperature loads from other circuit components that have high heatoutputs can be eliminated, and the effects on noise due to the powerswitch and the like can be reduced.

[0094] The interior of the electric power circuit 3 is a non-insulatedstructure, and is configured such that the controller 35 transmits datato and receives data from the exterior thereof via the communicationcircuit 36. Thus, the packaging density of each circuit component can beincreased and a reduction in the size of the module can be provided,because the communication circuit 36 insulates the electric powercircuit 3 from the exterior thereof and the insulating distance of themodule interior is shortened.

[0095] As noted above, a molding material that molds both the bare chipcomponents 311, 312 and the bare chip component 313 installed on themounting surface of the aluminum substrate 301 is provided on top of thealuminum substrate 301.

[0096] As shown in FIG. 2, if the printed wiring board 321 is installedon the mounting surface of the aluminum substrate 301 such that it isperpendicular thereto, the molding material can be arranged such that itcovers the bare chip components 311, 312 and the lead 322 of the printedwiring board 321 directly installed thereon. In addition, the moldingmaterial can also be structured such that one molding material coversbare chip components 311, 312 having equal thicknesses, and anothermolding material covers only the area around the printed wiring board321. In this situation, it is preferable that the molding material thatcovers only the area around the printed circuit board 321 be moreadhesive than the molding material that covers the bare chip components311, 312.

[0097] In addition, as shown in FIG. 3, if the printed wiring board 321is disposed parallel with respect to the mounting surface of thealuminum substrate 301, a molding material can be provided that coversall of the circuit components. Moreover, a molding material can beprovided that covers only the bare chip components 311, 312 and the lead322 provided on the printed wiring board 321. Furthermore, the moldingmaterial can also be structured such that one molding material coversbare chip components 311, 312 having equal thicknesses, and anothermolding material covers only the area around the printed wiring board321. In this situation also, it is preferable that the molding materialthat covers only the area around the printed circuit board 321 be moreadhesive than the molding material that covers the bare chip components311, 312.

[0098] The molding material is comprised of an insulating syntheticresin. For example, a silicone or epoxy resin can be employed.

[0099] The molding material can be applied such that it covers eachcircuit component mounted on the aluminum substrate 301. However, inorder to achieve improved insulation capabilities, a case can be formedon the upper surface of the aluminum substrate 301, and the moldingmaterial can be disposed inside the case. An example of thisconfiguration is shown in FIG. 4.

[0100] As shown in FIG. 4, side walls 351, 352, 353, 354 are formed onthe edges of the aluminum substrate 301 and extend toward the mountingsurface side thereof. Side walls 351-354 can be formed from aluminumnitride, like the aluminum substrate 301, or can be formed from aninsulating synthetic resin. In addition, the side walls 351-354 arefixed to the respective edges of the aluminum substrate 301 by thermallymelting them thereto, adhering them thereto, or the like, and theportions of the side walls 351-354 that are adjacent thereto are fixedto each other by means of thermal melting, adhesives, or the like sothat there are no gaps therebetween. Note that it is also possible tounitarily mold the side walls 351-354 such that they are integral witheach other.

[0101] As noted above, the molding material 341 is disposed in the emptyspace on the mounting surface side of the aluminum substrate 301 that isformed by the aluminum substrate 301 and the side walls 351-354. Themolding material 341 is arranged such that it covers the bare chipcomponents 311, 312, etc. that are mounted on the aluminum substrate 301as well as their wiring portions.

[0102] This configuration prevents the infiltration of corrosion, dust,and small animals therein, and also prevents accidents such as cut wiresand short-circuiting. In addition, a frame structure that surrounds thealuminum substrate 301 can be formed with side walls 351-354 that areintegrally formed or in which each side is combined with the others, anda case can be formed for mold filling by fixing the side walls 351-354to the aluminum substrate such that there are no gaps therebetween.Thus, all surfaces of the bare chip components 311, 312, etc. and theirwiring portions can be easily covered, and reliability will be improvedthereby. Furthermore, a case structure can be achieved by means of theside walls 351-354 and the aluminum substrate 301, and the thickness ofthe molding can be freely adjusted so that it covers each circuitcomponent to a necessary and sufficient degree. In other words, by usingthe side walls 351-354 that surround the periphery of the aluminumsubstrate 301 to prevent the molding material from flowing out, thethickness of the molding material can be freely adjusted.

[0103] As shown in FIG. 5, side walls 361-364 that are comprised of asynthetic resin in which a conductive pattern formed of copper has beenembedded therein can be substituted for the side walls 351-354 shown inFIG. 4.

[0104] The side walls 361-364 are formed by inserting a conductivepattern made of copper sheet into a metal mold, and then integrallymolding the side walls 361-364 by using a insulating synthetic resin.The side walls 361-364 can also be molded individually, or can be moldedso that they are all integral with each other. The side walls 361-364that are formed in this manner are fixed to the aluminum substrate 301by means of thermal melting, adhesives, screws, or the like. Preferably,the case is structured such that there are no gaps between the aluminumsubstrate 301 and the side walls 361-364, and between the portions ofthe side walls 361-364 that are adjacent to each other.

[0105] The molding material 341 is placed into the space on the mountingsurface side of the aluminum substrate 301 that is formed by thealuminum substrate 301 and the side walls 361-364. The molding material341 is disposed such that it covers the bare chip components 311, 312,etc. that are mounted on the aluminum substrate 301 and their wiringportions.

[0106] The conductive pattern embedded in the interior of the side walls361-364 forms a wiring pattern for installing large external circuitcomponents 371-373 such as electrolytic capacitors. Thus, these externalcircuit components 371-373 can be installed at the proper positions onthe side walls 361-364 with solder or the like. FIG. 5 shows an examplein which the external circuit components 371-373 are installed on theouter surface of the side wall 361. However, if there is open spaceabove the molding material 341, it is also possible to install theexternal circuit components on the interior surfaces of the side walls361-364.

[0107] This arrangement makes three dimensional mounting of componentspossible by mounting the circuit components on the side surfaces of thecase of the module, and can increase the integration ratio. In addition,this arrangement can also serve as an installation retention unit forcircuit components such as large electrolytic condensers, therebyincreasing the integration ratio, and reducing the size of the device.

[0108] In this embodiment, it is also possible to substitute a ceramicsubstrate or the like for the aluminum substrate 301.

[0109] (Aluminum Substrate)

[0110] If an aluminum substrate is used as the mounting substrate onwhich bare chip components 311, 312, printed wiring board 321, and thelike are mounted, a corrugated section can be disposed on the oppositesurface thereof in order to form a heat dissipation surface. Examples ofheat dissipation surfaces that are formed by corrugated sections areshown in FIGS. 6 to 10.

[0111] An aluminum substrate 401 shown in FIG. 6 has a power module 300mounted thereon that has, as noted above, been molded from a syntheticresin. A corrugated section 404 comprised of protrusions 402 that arerectangular in cross-section and formed parallel to each other, andgrooves 403 that are formed in between adjacent protrusions 402, isformed on the lower surface of the aluminum substrate 401.

[0112] The corrugated section 404 has a large surface area and a greatlyimproved heat dissipation efficiency, because of the protrusions 402that are rectangular in cross-section and formed parallel to each other,and grooves 403 that are formed in between adjacent protrusions 402.

[0113] An aluminum substrate 411 shown in FIG. 7 has a power module 300mounted thereon that has, as noted above, been molded from a syntheticresin. A corrugated section 414 comprised of protrusions 412 that aretriangular in cross-section and formed parallel to each other, andgrooves 413 that are formed in between adjacent protrusions 412, isformed on the lower surface of the aluminum substrate 411.

[0114] The corrugated section 414 has a large surface area and a greatlyimproved heat dissipation efficiency, because of the protrusions 412that are triangular in cross-section formed parallel to each other, andgrooves 413 that are formed in between adjacent protrusions 412.

[0115] An aluminum substrate 421 shown in FIG. 8 has a power module 300mounted thereon that has, as noted above, been molded from a syntheticresin. A corrugated section 424 comprised of protrusions 422 that aretrapezoidal in cross-section and formed parallel to each other, andgrooves 423 that are formed in between adjacent protrusions 422, isformed on the lower surface of the aluminum substrate 421.

[0116] The corrugated section 424 has a large surface area and a greatlyimproved heat dissipation efficiency, because of the protrusions 422that are trapezoidal in cross-section and formed parallel to each other,and grooves 423 that are formed in between adjacent protrusions 422.

[0117] An aluminum substrate 431 shown in FIG. 9 has a power module 300mounted thereon that has, as noted above, been molded from a syntheticresin. A corrugated section 434 comprised of protrusions 432 that aresemicircular in cross-section and formed parallel to each other, andgrooves 433 that are formed in between adjacent protrusions 432, isformed on the lower surface of the aluminum substrate 431.

[0118] The corrugated section 434 has a large surface area and a greatlyimproved heat dissipation efficiency, because of the protrusions 432that are semicircular in cross-section and formed parallel to eachother, and grooves 433 that are formed in between adjacent protrusions432.

[0119] An aluminum substrate 441 shown in FIG. 10 has a power module 300mounted thereon that has, as noted above, been molded from a syntheticresin. A corrugated section 444 comprised of a plurality of protrusions442 that have a hemisphere formed on each of the tips thereof is formedon the lower surface of the aluminum substrate 441.

[0120] The corrugated section 444 has a large surface area and a greatlyimproved heat dissipation efficiency because of the protrusions 442.

[0121] (Heat Dissipating Fins)

[0122] Heat dissipating fins that are comprised of an attachment surfacewhich attaches to a corrugated section provided on the lower surface ofthe aluminum substrate, and a plurality of plate shaped fins, can beinstalled on the lower surface of the aluminum substrate. Examples ofthis type of heat dissipating fins are shown in FIGS. 11-15.

[0123] The heat dissipating fins 501 shown in FIG. 11 are installed onthe aluminum substrate 401 shown in FIG. 6, and comprise an attachmentsurface 504 on one side thereof that attaches to the corrugated section404 of the aluminum substrate 401. The attachment surface 504 iscomprised of protrusions 502 that are rectangular in cross-section andfit into the grooves 403 of the aluminum substrate 401, and grooves 503that accept the protrusions 402 of the aluminum substrate 401. Theattachment surface 504 can be adhered to the corrugated section 404 ofthe aluminum substrate 401.

[0124] The heat dissipating fins 501 are comprised of a plurality ofplate shaped fin members 505 that project from the side opposite theattachment surface 504. The fin members 505 are formed to be thin inorder to enlarge the surface area, and are disposed with a predetermineddistance between each other in order to increase the heat dissipationefficiency thereof.

[0125] The heat dissipating fins 501, like the aluminum substrate 401,can be comprised of a material such as aluminum nitride having highthermal conductivity and excellent insulation characteristics, and canbe produced with a processing method such as drawing or punching.

[0126] The heat dissipating fins 501 are attached such that theattachment surface 504 is adhered to the corrugated section 404 of thealuminum substrate 401, and are adhered thereto with an attachmentmethod such as screwing, thermal melting, or by means of a resinmaterial.

[0127] When constructed in this manner, there is a large attachmentsurface area between the corrugated section 404 of the aluminumsubstrate 401 and the attachment surface 504 of the heat dissipatingfins 501, and thus the thermal conduction efficiency from the aluminumsubstrate 401 to the heat dissipating fins 501 will be excellent, andthe heat generated by the power module 300 can be dissipated moreefficiently with the fin members 505 of the heat dissipating fins 501.

[0128] The heat dissipating fins 511 shown in FIG. 12 are installed onthe aluminum substrate 411 shown in FIG. 7, and comprise an attachmentsurface 514 on one side thereof that attaches to the corrugated section414 of the aluminum substrate 411. The attachment surface 514 iscomprised of protrusions 512 that are triangular in cross-section andfit into the grooves 413 of the aluminum substrate 411, and grooves 513that accept the protrusions 412 of the aluminum substrate 411. Theattachment surface 514 can be adhered to the corrugated section 414 ofthe aluminum substrate 411.

[0129] The heat dissipating fins 511 are comprised of a plurality ofplate shaped fin members 515 that project from the side opposite theattachment surface 514. The fin members 515 are formed to be thin inorder to enlarge the surface area, and are disposed with a predetermineddistance between each other in order to increase the heat dissipationefficiency thereof.

[0130] The heat dissipating fins 511, like the heat dissipating fins 501noted above, can be comprised of a material such as aluminum nitridehaving high thermal conductivity and excellent insulationcharacteristics, and can be produced with a processing method such asdrawing or punching.

[0131] The heat dissipating fins 511 are attached such that theattachment surface 514 is adhered to the corrugated section 414 of thealuminum substrate 411, and are adhered thereto with an attachmentmethod such as screwing, thermal melting, or by means of a resinmaterial.

[0132] When constructed in this manner, there is a large attachmentsurface area between the corrugated section 414 of the aluminumsubstrate 411 and the attachment surface 514 of the heat dissipatingfins 511, and thus the thermal conduction efficiency from the aluminumsubstrate 411 to the heat dissipating fins 511 will be excellent, andthe heat generated by the power module 300 can be dissipated moreefficiently with the fin members 515 of the heat dissipating fins 511.

[0133] The heat dissipating fins 521 shown in FIG. 13 are installed onthe aluminum substrate 421 shown in FIG. 8, and comprise an attachmentsurface 524 on one side thereof that attaches to the corrugated section424 of the aluminum substrate 421. The attachment surface 524 iscomprised of protrusions 522 that are trapezoidal in cross-section andfit into the grooves 423 of the aluminum substrate 421, and grooves 523that accept the protrusions 422 of the aluminum substrate 421. Theattachment surface 524 can be adhered to the corrugated section 424 ofthe aluminum substrate 421.

[0134] The heat dissipating fins 521 are comprised of a plurality ofplate shaped fin members 525 that project from the side opposite theattachment surface 524. The fin members 525 are formed to be thin inorder to enlarge the surface area, and are disposed with a predetermineddistance between each other in order to increase the heat dissipationefficiency thereof.

[0135] The heat dissipating fins 521, like the heat dissipating fins 501noted above, can be comprised of a material such as aluminum nitridehaving high thermal conductivity and excellent insulationcharacteristics, and can be produced with a processing method such asdrawing or punching.

[0136] The heat dissipating fins 521 are attached such that theattachment surface 524 is adhered to the corrugated section 424 of thealuminum substrate 421, and are adhered thereto with an attachmentmethod such as screwing, thermal melting, or by means of a resinmaterial.

[0137] When constructed in this manner, there is a large attachmentsurface area between the corrugated section 424 of the aluminumsubstrate 421 and the attachment surface 524 of the heat dissipatingfins 521, and thus the thermal conduction efficiency from the aluminumsubstrate 421 to the heat dissipating fins 521 will be excellent, andthe heat generated by the power module 300 can be dissipated moreefficiently with the fin members 525 of the heat dissipating fins 521.

[0138] The heat dissipating fins 531 shown in FIG. 14 are installed onthe aluminum substrate 431 shown in FIG. 9, and comprise an attachmentsurface 534 on one side thereof that attaches to the corrugated section434 of the aluminum substrate 431. The attachment surface 534 iscomprised of protrusions 532 that are semicircular in cross-section andfit into the grooves 433 of the aluminum substrate 431, and grooves 533that accept the protrusions 432 of the aluminum substrate 431. Theattachment surface 534 can be adhered to the corrugated section 434 ofthe aluminum substrate 431.

[0139] The heat dissipating fins 531 are comprised of a plurality ofplate shaped fin members 535 that project from the side opposite theattachment surface 534. The fin members 535 are formed to be thin inorder to enlarge the surface area, and are disposed with a predetermineddistance between each other in order to increase the heat dissipationefficiency thereof.

[0140] The heat dissipating fins 531, like the heat dissipating fins 501noted above, can be comprised of a material such as aluminum nitridehaving high thermal conductivity and excellent insulationcharacteristics, and can be produced with a processing method such asdrawing or punching.

[0141] The heat dissipating fins 531 are attached such that theattachment surface 534 is adhered to the corrugated section 434 of thealuminum substrate 431, and are adhered thereto with an attachmentmethod such as screwing, thermal melting, or by means of a resinmaterial.

[0142] When constructed in this manner, there is a large attachmentsurface area between the corrugated section 434 of the aluminumsubstrate 431 and the attachment surface 534 of the heat dissipatingfins 531, and thus the thermal conduction efficiency from the aluminumsubstrate 431 to the heat dissipating fins 531 will be excellent, andthe heat generated by the power module 300 can be dissipated moreefficiently with the fin members 535 of the heat dissipating fins 531.

[0143] The heat dissipating fins 541 shown in FIG. 15 are installed onthe aluminum substrate 441 shown in FIG. 10, and comprise an attachmentsurface 544 on one side thereof that attaches to the corrugated section444 of the aluminum substrate 441. The attachment surface 544 iscomprised of a plurality of concave portions 543 into which fit theprotrusions 442 of the aluminum substrate 441. The attachment surface544 can be adhered to the corrugated section 444 of the aluminumsubstrate 441.

[0144] The heat dissipating fins 541 are comprised of a plurality ofplate shaped fin members 545 that project from the side opposite theattachment surface 544. The fin members 545 are formed to be thin inorder to enlarge the surface area, and are disposed with a predetermineddistance between each other in order to increase the heat dissipationefficiency thereof.

[0145] The heat dissipating fins 541, like the heat dissipating fins 501noted above, can be comprised of a material such as aluminum nitridehaving high thermal conductivity and excellent insulationcharacteristics, and can be produced with a processing method such asdrawing or punching.

[0146] The heat dissipating fins 541 are attached such that theattachment surface 544 is adhered to the corrugated section 444 of thealuminum substrate 441, and are adhered thereto with an attachmentmethod such as screwing, thermal melting, or by means of a resinmaterial.

[0147] When constructed in this manner, there is a large attachmentsurface area between the corrugated section 444 of the aluminumsubstrate 441 and the attachment surface 544 of the heat dissipatingfins 541, and thus the thermal conduction efficiency from the aluminumsubstrate 441 to the heat dissipating fins 541 will be excellent, andthe heat generated by the power module 300 can be dissipated moreefficiently with the fin members 545 of the heat dissipating fins 541.

[0148] (Attachment Structure for Aluminum Substrate and Heat DissipatingFins)

[0149] Attachment structures for installing the heat dissipating fins tothe heat dissipating surface of the aluminum substrate that aredifferent than the embodiments noted above can be considered. Forexample, assume that each of the tips of the protrusions provided on theheat dissipating surface of the aluminum substrate have a shape incross-section that bulges out toward the sides thereof further than thebase thereof, and that the shape of each groove positioned between eachprotrusion allows each protrusion provided on the attachment surface ofthe heat dissipating fins to be received therein. Further assume thatwith the protrusions provided on the attachment surface of the heatdissipating fins, each of the tips thereof have a shape in cross-sectionthat bulges out toward the sides thereof further than the base thereof,and that the shape of each groove positioned between each protrusionallows each protrusion provided on the aluminum substrate to be receivedtherein. This configuration allows the aluminum substrate and the heatdissipating fins to be maintained in the attached state even if noscrews are used. Embodiments of this configuration are described inFIGS. 16-18.

[0150] An aluminum substrate 451 shown in FIG. 16 mounts the powermodule 300 that was molded by means of the synthetic resin noted above.A corrugated section 456 is formed on the lower surface thereof, whichcomprises protrusions 454 that are formed such that they are parallelwith each other, and grooves 455 that are formed between adjacentprotrusions 454. Each protrusion 454 is comprised of a base 452 and atip 453 that bulges out toward the sides further than the base 452, andare T shaped in cross-section.

[0151] The heat dissipating fins 551 have, on one surface thereof, anattachment surface 556 that attaches to the corrugated section 456 ofthe aluminum substrate 451. The attachment surface 556 is comprised ofprotrusions 554 that fit into the grooves 455 of the aluminum substrate451, and grooves 555 that receive the protrusions 454 of the aluminumsubstrate 451. The attachment surface 556 can be adhered to thecorrugated section 456 of the aluminum substrate 451. Each protrusion554 is comprised of a base 552 and a tip 553 that bulges out toward thesides further than the base 552, and are T shaped in cross-section.

[0152] The heat dissipating fins 551 are comprised of a plurality ofplate shaped fin members 557 that project from the side opposite theattachment surface 556. The fin members 557 are formed to be thin inorder to enlarge the surface area, and are disposed with a predetermineddistance between each other in order to increase the heat dissipationefficiency thereof.

[0153] The heat dissipating fins 557, like the aluminum substrate 451,can be comprised of a material such as aluminum nitride having highthermal conductivity and excellent insulation characteristics, and canbe produced with a processing method such as drawing or punching.

[0154] The protrusions 454 of the aluminum substrate 451 are fitted intothe grooves 555 of the heat dissipating fins 551. By fitting theprotrusions 554 of the heat dissipating fins 551 into the grooves 455 ofthe aluminum substrate 451, and sliding each protrusion 454, 554parallel to each other, the attachment surface 556 of the heatdissipating fins 551 can be attached to the corrugated section 456 ofthe aluminum substrate 451.

[0155] Thus, by engaging the protrusions 454 and grooves 455 of thealuminum substrate 451 and the protrusions 554 and grooves 555 of theheat dissipating fins 551, movement that separates the aluminumsubstrate 451 and the heat dissipating fins 551 can be regulated, andthus they can be maintained in the attached state. In this way, thethermal conduction efficiency between the aluminum substrate 451 and theheat dissipating fins 551 can be maintained at a high level, and screwsand the like used for installation can be omitted.

[0156] An aluminum substrate 461 shown in FIG. 17 mounts the powermodule 300 that was molded by means of the synthetic resin noted above.A corrugated section 466 is formed on the lower surface thereof, whichcomprises protrusions 464 that are formed such that they are parallelwith each other, and grooves 465 that are formed between adjacentprotrusions 464. Each protrusion 464 is comprised of a base 462 and atip 463 that bulges out toward the sides further than the base 462. Theprotrusions 464 and the grooves 465 are shaped such that a cross-sectionof the corrugated section 466 is a combination of round or ellipticalcurves.

[0157] The heat dissipating fins 561 have, on one surface thereof, anattachment surface 566 that attaches to the corrugated section 466 ofthe aluminum substrate 461. The attachment surface 566 is comprised ofprotrusions 564 that fit into the grooves 465 of the aluminum substrate461, and grooves 565 that receive the protrusions 464 of the aluminumsubstrate 461. The attachment surface 566 can be adhered to thecorrugated section 466 of the aluminum substrate 461. Each protrusion564 is comprised of a base 562 and a tip 563 that bulges out toward thesides further than the base 562. The protrusions 564 and the grooves 565are shaped such that a cross-section of the corrugated section 566 is acombination of round or elliptical curves.

[0158] The heat dissipating fins 561 are comprised of a plurality ofplate shaped fin members 567 that project from the side opposite theattachment surface 566. The fin members 567 are formed to be thin inorder to enlarge the surface area, and are disposed with a predetermineddistance between each other in order to increase the heat dissipationefficiency thereof.

[0159] The heat dissipating fins 567, like the aluminum substrate 461,can be comprised of a material such as aluminum nitride having highthermal conductivity and excellent insulation characteristics, and canbe produced with a processing method such as drawing or punching.

[0160] Like with the aforementioned embodiment, the protrusions 464 ofthe aluminum substrate 461 are fitted into the grooves 565 of the heatdissipating fins 561. By fitting the protrusions 564 of the heatdissipating fins 561 into the grooves 465 of the aluminum substrate 461,and sliding each protrusion 464, 564 parallel to each other, theattachment surface 566 of the heat dissipating fins 561 can be attachedto the corrugated section 466 of the aluminum substrate 461.

[0161] Thus, by engaging the protrusions 464 and grooves 465 of thealuminum substrate 461 and the protrusions 564 and grooves 565 of theheat dissipating fins 561, movement that separates the aluminumsubstrate 461 and the heat dissipating fins 561 can be regulated, andthus they can be maintained in the attached state. In this way, thethermal conduction efficiency between the aluminum substrate 461 and theheat dissipating fins 561 can be maintained at a high level, and screwsand the like used for installation can be omitted.

[0162] An aluminum substrate 471 shown in FIG. 18 mounts the powermodule 300 that was molded by means of the synthetic resin noted above.A corrugated section 476 is formed on the lower surface thereof, whichcomprises protrusions 472 that are formed such that they are parallelwith each other, and grooves 473 that are formed between adjacentprotrusions 472. Each protrusion 472 is comprised of an upside downtrapezoid (in cross-section) that bulges out toward the sides furtherthan the base thereof.

[0163] The heat dissipating fins 561 have, on one surface thereof, anattachment surface 574 that attaches to the corrugated section 476 ofthe aluminum substrate 471. The attachment surface 574 is comprised ofprotrusions 572 that fit into the grooves 473 of the aluminum substrate471, and grooves 573 that receive the protrusions 472 of the aluminumsubstrate 471. The attachment surface 574 can be adhered to thecorrugated section 474 of the aluminum substrate 471. Each protrusion572 is comprised of an upside down trapezoid (in cross-section) thatbulges out toward the sides further than the base thereof.

[0164] The heat dissipating fins 571 are comprised of a plurality ofplate shaped fin members 575 that project from the side opposite theattachment surface 574. The fin members 575 are formed to be thin inorder to enlarge the surface area, and are disposed with a predetermineddistance between each other in order to increase the heat dissipationefficiency thereof.

[0165] The heat dissipating fins 571, like the aluminum substrate 471,can be comprised of a material such as aluminum nitride having highthermal conductivity and excellent insulation characteristics, and canbe produced with a processing method such as drawing or punching.

[0166] Like with the aforementioned embodiment, the protrusions 472 ofthe aluminum substrate 471 are fitted into the grooves 573 of the heatdissipating fins 571. By fitting the protrusions 573 of the heatdissipating fins 571 into the grooves 472 of the aluminum substrate 471,and sliding each protrusion 472, 572 parallel to each other, theattachment surface 574 of the heat dissipating fins 571 can be attachedto the corrugated section 474 of the aluminum substrate 471.

[0167] Thus, by engaging the protrusions 472 and grooves 473 of thealuminum substrate 471 and the protrusions 572 and grooves 573 of theheat dissipating fins 571, movement that separates the aluminumsubstrate 471 and the heat dissipating fins 571 can be regulated, andthus they can be maintained in the attached state. In this way, thethermal conduction efficiency between the aluminum substrate 471 and theheat dissipating fins 571 can be maintained at a high level, and screwsand the like used for installation can be omitted.

[0168] The shapes of the corrugated section of the aluminum substrateand the heat dissipating fins are not limited to the shapes shown in thefigures, but can be any shape that provides excellent thermal conductionefficiency. In addition, the circuit structure inside the module is notlimited to that shown in the figures, and the corrugated section of thealuminum substrate and the heat dissipating fins can be applied to avariety of modules which comprise circuit components that are thought toproduce a great deal of heat.

[0169] As shown in FIG. 19, heat dissipating fins 331 can be simplyattached directly to the surface opposite the mounting surface of thealuminum substrate 301. The heat dissipating fins 331 can be integrallyand simultaneously formed with the aluminum nitride plate that forms thealuminum substrate 301, or can be attached to the aluminum substrate 301by thermally melting them thereto or adhering them thereto.

[0170] If the heat dissipating plates 301 are formed to be integral withthe surface opposite the bare chip component mounting surface of thealuminum substrate 301, it will not be necessary to install separateheat dissipating fins, and it will be possible to improve the heatconduction efficiency of the aluminum substrate 301.

INDUSTRIAL APPLICABILITY

[0171] In the power module according to claim 1 of the presentinvention, the connection between the bare chip components and thewiring on the mounting substrate can be formed by wire bonding and thelike. Because this wiring is molded by means of the molding material,the wiring can be shortened and the effects of noise can be eliminated.In addition, because exposed portions will be eliminated, the effectsfrom the infiltration of corrosion, dust, and small animals can beprevented.

[0172] In the power module according to claim 2 of the presentinvention, the connection between the bare chip components and thewiring on the mounting substrate can be formed by wire bonding and thelike. Because this wiring is molded by means of the molding material,the wiring can be shortened. When a large number of components generateheat, the power module can be constructed such that the heat isdissipated via the aluminum substrate.

[0173] In the power module according to claim 3 of the presentinvention, circuit components that produce a great deal of heat can beinsulated from those that produce comparatively little heat by formingthe printed wiring board on which the comparatively low heat generatingcircuit components are mounted into a hybrid shape.

[0174] In the power module according to claim 4 of the presentinvention, if comparatively high heat generating circuit components aremounted on top of the mounting substrate as bare chip components, heatcan be efficiently dissipated therefrom via the heat dissipating fins,and circuit malfunctions can be prevented by maintaining them at asuitable temperature.

[0175] In the power module according to claim 5 of the presentinvention, the task of filling the space formed by the mountingsubstrate and the side walls with the molding material can be made easy,and the bare chip component mounting surface of the mounting substratecan be accurately molded.

[0176] In the power module according to claim 6 of the presentinvention, it is possible to use the conductive pattern embedded in theinterior of the side walls to connect the circuit elements, and it ispossible to mount circuit elements such as electrolytic condensers andthe like that are difficult to integrate.

[0177] In the power module according to claim 7 of the presentinvention, by directly mounting the inverter circuit and the controllerfor the inverter circuit to the mounting substrate as bare chipcomponents and modulizing them, it will not be necessary to againconsider the spatial layout and thermal design of each component, theill effects of noise will be eliminated to the greatest degree possibleby shortening the wiring distances, and ill effects from theinfiltration of corrosion, dust and small animals will be prevented.

[0178] In the power module according to claim 8 of the presentinvention, each power module can be comprised of one or a plurality ofbare chip components, and the bare chip components can be mounted on thealuminum substrate. Thus, it will not be necessary to again consider thespatial layout and thermal designs thereof.

[0179] In the power module according to claim 9 of the presentinvention, by modulizing the inverter circuit that controls thecompressor of the air conditioner, the size of the device can bereduced, the ill effects of noise and the ill effects from theinfiltration of corrosion, dust and small animals can be eliminated, anda highly reliable device can be provided. In addition, by viewing thepower module as one component and conducing structural designaccordingly, it will not be necessary to have a different structuraldesign for each type of compressor mounted in the air conditioner, andthus the number of man-hours needed for structural design with respectto the large number of different types of compressors available can begreatly reduced.

[0180] In the power module according to claim 10 of the presentinvention, the size of the device can be reduced by mounting the fanmotor controller comprising bare chip components onto the aluminumsubstrate together with other circuit components and modulizing them,thus eliminating the need to again consider the spatial layout andthermal design thereof.

[0181] In the air conditioner according to claim 11 of the presentinvention, by modulizing the electric power unit of the air conditioner,the size of the device can be reduced, the ill effects of noise and theill effects from the infiltration of corrosion, dust and small animalscan be eliminated, and a highly reliable device can be provided.

[0182] In the air conditioner according to claim 12 of the presentinvention, the ill effects of noise can be eliminated by modulizing theelectric power unit that serves to control the electric power suppliedto the compressor of the air conditioner. In addition, foreign objectssuch as small animals and dust that enter into the electric power unitand cause problems such as short circuiting and the like can beprevented.

[0183] In the air conditioner according to claim 13 of the presentinvention, the size of the device can be reduced by including and thenmodulizing the fan motor controller that controls the rotation of thefan motor of the air conditioner, and thus a highly reliable device inwhich the ill effects of noise and the ill effects of the infiltrationof corrosion, dust, and small animals are eliminated.

[0184] In the power module according to claim 14 of the presentinvention, the heat generated by the circuit components mounted on themounting surface can be efficiently dissipated by means of thecorrugated section formed on the heat dissipating surface of themounting substrate.

[0185] In the power module according to claim 15 of the presentinvention, heat can be efficiently dissipated from the heat dissipationsurface even if the mounting surface is molded with an insulatingsynthetic resin and an enclosed type of module is formed.

[0186] In the power module according to claim 16 of the presentinvention, the heat from the circuit components mounted on the mountingsurface can be efficiently dissipated because an aluminum having a highthermo-electric conductivity is used as the mounting substrate.

[0187] In the power module according to claim 17 of the presentinvention, the attachment surface of the heat dissipating fins has acorrugated shape such that it attaches to the heat dissipating surfaceof the mounting substrate, and the thermal conductive efficiency betweenthe heat dissipating fins and the mounting substrate is improved. Thus,the heat generated from the circuit components mounted on the mountingsubstrate can be efficiently transmitted to the heat dissipating fins,and the efficiency of thermal dissipation can be improved.

[0188] In the power module according to claim 18 of the presentinvention, the surface area of the heat dissipating fins of the mountingsubstrate can be enlarged, and the heat dissipation efficiency can beimproved, by means of the protrusions that are rectangular incross-section and the grooves formed in between the adjacentprotrusions. In addition, when the heat dissipating fins are installed,the thermal dissipation effect can be improved because the contactsurface area between the heat dissipating surface of the mountingsubstrate and the attachment surface of the heat dissipating fins isenlarged, and the mutual thermal transmission efficiency is improved.

[0189] In the power module according to claim 19 of the presentinvention, the surface area of the heat dissipating fins of the mountingsubstrate can be enlarged, and the heat dissipation efficiency can beimproved, by means of the protrusions that are triangular incross-section and the grooves formed in between the adjacentprotrusions. In addition, when the heat dissipating fins are installed,the thermal dissipation effect can be improved because the contactsurface area between the heat dissipating surface of the mountingsubstrate and the attachment surface of the heat dissipating fins isenlarged, and the mutual thermal transmission efficiency is improved.

[0190] In the power module according to claim 20 of the presentinvention, the surface area of the heat dissipating fins of the mountingsubstrate can be enlarged, and the heat dissipation efficiency can beimproved, by means of the protrusions that are trapezoidal incross-section and the grooves formed in between the adjacentprotrusions. In addition, when the heat dissipating fins are installed,the thermal dissipation effect can be improved because the contactsurface area between the heat dissipating surface of the mountingsubstrate and the attachment surface of the heat dissipating fins isenlarged, and the mutual thermal transmission efficiency is improved.

[0191] In the power module according to claim 21 of the presentinvention, the surface area of the heat dissipating fins of the mountingsubstrate can be enlarged, and the heat dissipation efficiency can beimproved, by means of the protrusions that are semi-circular incross-section and the grooves formed in between the adjacentprotrusions. In addition, when the heat dissipating fins are installed,the thermal dissipation effect can be improved because the contactsurface area between the heat dissipating surface of the mountingsubstrate and the attachment surface of the heat dissipating fins isenlarged, and the mutual thermal transmission efficiency is improved.

[0192] In the power module according to claim 22 of the presentinvention, the surface area of the heat dissipating fins of the mountingsubstrate can be enlarged, and the heat dissipation efficiency can beimproved, by means of the protrusions that are hemispherical incross-section and the grooves formed in between the adjacentprotrusions. In addition, when the heat dissipating fins are installed,the thermal dissipation effect can be improved because the contactsurface area between the heat dissipating surface of the mountingsubstrate and the attachment surface of the heat dissipating fins isenlarged, and the mutual thermal transmission efficiency is improved.

[0193] In the power module according to claim 23 of the presentinvention, the surface area of the heat dissipating fins of the mountingsubstrate can be enlarged, and the heat dissipation efficiency can beimproved, by means of the protrusions whose tips are shaped incross-section to bulge outward, with respect to the bases thereof,toward the sides and the grooves are received in between the adjacentprotrusions. In addition, by fitting the protrusions and grooves of therespective mounting substrate and heat dissipating fins, movement thatseparates the two members can be regulated, and thus they can bemaintained in the attached state without the use of attachment meanssuch as screws and the like.

1. A power module, comprising: a bare chip component that comprises anelectrical power circuit for controlling electrical power; a mountingsubstrate on which the bare chip component is mounted; and a moldingmaterial comprised of an insulating resin that molds to the surface ofthe mounting substrate on which the bare chip component is mounted. 2.The power module according to claim 1, wherein a plurality of bare chipcomponents are mounted on the mounting substrate.
 3. The power moduleaccording to claim 1 or 2, wherein the bare chip component includes anIC chip that is mounted on a printed wiring board that is mounted on themounting surface.
 4. The power module according to any of claims 1 to 3,wherein the mounting substrate comprises heat dissipating fins that areintegrally disposed on a surface opposite the surface on which the barechip component is mounted.
 5. The power module according to any ofclaims 1 to 4, further comprising side walls that are disposed on edgesof the mounting substrate and which extend above the surface on whichthe bare chip is mounted; wherein the molding material is disposedinside a space formed by the mounting substrate and the side walls. 6.The power module according to claim 5, wherein the side walls arecomprised of plate shaped members that are formed from a synthetic resinand in which a conductive pattern is embedded.
 7. The power moduleaccording to any of claims 1 to 6, wherein the bare chip componentcomprises an inverter circuit that converts commercial ac power to acpower having a predetermined frequency, and a controller that controlsthe frequency output from the inverter circuit.
 8. The power moduleaccording to claim 7, wherein the inverter circuit is comprised of aconverter that rectifies commercial ac power to dc power, an inverterthat converts the output of the converter to ac power, a converterdriver that drives the converter, and an inverter driver that drives theinverter.
 9. The power module according to claim 7 or 8, wherein theinverter circuit controls electric power supplied to a compressor in anair conditioner, the compressor controlling an amount of refrigerantcirculating in a refrigerant circuit.
 10. The power module according toclaim 9, wherein the air conditioner is comprised of a fan that producesan air flow that exchanges heat with refrigerant inside a heat exchangerdisposed inside the refrigerant circuit, and a fan motor that rotativelydrives the fan; wherein the bare chip component further includes a fanmotor controller that controls rotation of the fan motor.
 11. An airconditioner having an air conditioning unit that exchanges heat betweenair drawn therein and refrigerant that circulates inside a refrigerantcircuit and then supplies heat exchanged air to an indoor space, and anelectric power unit that controls electric power supplied to the airconditioning unit, the electric power unit comprising: a modulized powermodule that is comprised of: a bare chip component that comprises anelectric power circuit for controlling electric power; a mountingsubstrate on which the bare chip component is mounted; and a moldingmaterial that is comprised of an insulating resin and which molds to thesurface of the mounting substrate on which the bare chip component ismounted.
 12. The air conditioner according to claim 11, furthercomprising a compressor that controls the amount of refrigerantcirculating in the refrigerant circuit; wherein the bare chip componentcontrols electric power that is supplied to the compressor and iscomprised of an inverter circuit that converts commercial ac power to acpower of a predetermined frequency, and a controller that controls anoutput frequency of the inverter circuit.
 13. The air conditioneraccording to claim 11 or 12, further comprising a fan that produces anair flow that exchanges heat with refrigerant inside a heat exchangerdisposed inside the refrigerant circuit, and a fan motor that rotativelydrives the fan; and the bare chip component further comprises a fanmotor controller that controls rotation of the fan motor.
 14. A powermodule, comprising: a mounting substrate that is formed from a memberhaving a high thermal conduction efficiency and which comprises amounting surface on which an electric power circuit for controllingelectric power is mounted, and a heat dissipating surface on which acorrugated section for heat dissipation is formed.
 15. The power moduleaccording to claim 14, wherein the mounting surface and the heatdissipating surface comprise a two-sided mounting substrate.
 16. Thepower module according to claim 14 or 15, wherein the mounting substratecomprises a plate shaped substrate formed from an aluminum type of metaland which has a copper wiring pattern formed on one side thereof. 17.The power module according to any of claims 14 to 16, wherein heatdissipating fins comprising an attachment surface that attaches to theheat dissipating surface of the corrugated section, and a fin formationsection on which plate shaped fins are disposed, are installed on theheat dissipating surface of the mounting substrate.
 18. The power moduleaccording to any of claims 14 to 17, wherein the corrugated section iscomprised of plate shaped protrusions having rectangular cross-sectionsand which are formed parallel to each other, and grooves that are formedbetween adjacent protrusions.
 19. The power module according to any ofclaims 14 to 17, wherein the corrugated section is comprised of plateshaped protrusions having triangular cross-sections and which are formedparallel to each other, and grooves that are formed between adjacentprotrusions.
 20. The power module according to any of claims 14 to 17,wherein the corrugated section is comprised of plate shaped protrusionshaving trapezoidal cross-sections and which are formed parallel to eachother, and grooves that are formed between adjacent protrusions.
 21. Thepower module according to any of claims 14 to 17, in which thecorrugated section is comprised of plate shaped protrusions havingsemi-circular cross-sections and which are formed parallel to eachother, and grooves that are formed between adjacent protrusions.
 22. Thepower module according to any of claims 14 to 17, wherein the corrugatedsection is comprised of a plurality of protrusions having tips thereofthat are hemi-spherical in shape.
 23. The power module according toclaim 17, wherein the heat dissipating surface of the mounting substrateand the attachment surface of the heat dissipating fins compriseprotrusions whose tips have a shape in cross-section which bulge outwardtoward the sides, with respect to the bases thereof, and grooves whichare received in between adjacent protrusions.